Visual and audible alerting is not always effective in alerting employees, guests and others who are unfamiliar with an environment of emergencies and providing guidance to safe areas (evacuation routes or shelter in place). Other workplace hazards include, but are not limited to, the inability to see or hear the approach of vehicular traffic (e.g., forklift trucks). Further, the mandated use of personal protection equipment (PPE), such as glasses or goggles, hardhats, and hearing protection, can limit the wearer's awareness of visual/audible cues that are installed around factories, warehouses, construction areas and buildings.
Often times, signage is displayed around the facility in graphic as well as written form (may include language translations) to warn against hazardous areas, conditions or map evacuation routes/exits. However, ambient noise (sometimes combined with PPE) can raise the noise floor and reduce the awareness of nearby risks. Visitors and temporary workers who are unfamiliar with unsafe areas or areas of heavy traffic and are more likely to put themselves into harm's way, especially in emergency evacuation situations such as fire, explosions, inclement weather, or active shooter scenarios.
For employees and/or visitors donning PPE gear, including protective eyewear, headwear and hearing protection, peripheral awareness of traditional visual and audible alerts may be diminished and often requires the ‘buddy system’ means of notification. This is often true of welders or those working in extremely loud areas of a factory. In cases where announcements are used to precede an emergency notification, that announcement is lost during the time when the employee may still be wearing the PPE. Hence, the general alarm coupled with an announcement to shelter in place may be misinterpreted to evacuate the premise.